Combustible blank cartridge



March 18, TERUH|KO SU ET AL COMBUSTIBLE BLANK CARTRIDGE Filed April 18, 1967 Sheet of 2 March 18, 1969 TERUHIKO $UzUK| ET AL 3,433,156

COMBUSTIBLE BLANK CARTRIDGE Filed April 18, 1967 Sheet 3 of a F IG. 7 Hm.

United States Patent Oflice 3,433,156 Patented Mar. 18, 1969 3,433,156 COMBUSTIBLE BLANK CARTRIDGE Teruliiko Suzuki, Nobeoka-shi, Junichi Nomura and Daijiro Kameyama, Oita-shi, and Minorn Miyoshi, Sokashi, Japan, assignors to Asahi Kasei Kogyo Kabushiki Kaisha, Osaka, Japan, a corporation of Japan Filed Apr. 18, 1967, Ser. No. 631,750 Claims priority, application Japan, Apr. 21, 1966, 41/24,927; May 23, 1966, ll/32,435; Nov. 15, 1966, 41/ 104,775; Feb. 16, 1967, 42/12,413 US. Cl. 102-39 14 Claims Int. Cl. F42b 5/20, 9/18 ABSTRACT OF THE DISCLOSURE Production of a combustible blank cartridge is effected by preparing a firing sheet impregnated with priming composition, cutting a firing sheet into the form of a circular base having an appropriate size and adhering the circular base to the surface of one end of a solid propellant previously molded into a column-shape.

The present invention relates to a cartridge for ammunition and explosive devices, particularly to a blank cartridge of percussion type for small arms.

Blank cartridges for small arms are classified in general into two groups. One group includes those prepared by loading a metallic cartridge case such as a copper or brass cartridge case with priming composition and propellant, the other includes such those as prepared by loading a cartridge case with propellant and equipping the cartridge with a small arms primer. The former is generally known as a blank cartridge of rim fire type and,

the latter as a blank cartridge of center fire type. Each of blank cartridges of these types, however, suifers from an economical disadvantage in that the cost of production thereof is relatively high because of the use of an expensive metallic cartridge case. Still further, because a waste cartridge case must be unloaded after firing, it has the disadvantage that not only is handling of the gun troublesome but also the waste cartridge case is subject at times to defective unloading.

Recently, in order to overcome these drawbacks, combustible blank cartridges have been developed. In the field of combustible blank cartridges, such combustible blank cartridges as those having a cartridge case made of synthetic resin or combustible materials analogous thereto are known to the art. However, such case materials employed in blank cartridges of these types are poor in strength as compared with those of metallic cartridge cases. Furthermore, because of their low hardness, it has almost been impossible to design a blank cartridge of rim fire type, wherein a priming composition is percussed to ignite at a rim portion of the bottom of cartridge case. On the one hand, in the case of a blank cartridge of center fire type, it is necessary to use a primer containing an incombustible material or at least a metallic anvil in order to facilitate ignition of a priming composition by percussion. By reason of the above, it has been difiicult to design a completely combustible blank cartridge not containing some incombustible material. A blank cartridge of this type in which any anvil is not employed cannot provide sufiicient percussion sensitivity, and consequently, it is presently still out of practical use.

This invention relates to a blank cartridge of percussion type, particularly to a completely combustible case less blank cartridge.

The blank cartridge of this invention is characterized in that it consists of a solid propellant previously molded into a cylindrical shape, to one end of which a firing sheet prepared by impregnating or coating a padding material with a priming composition is adhered and, from the structural point of view, at least one portion of said firing sheet is not covered by the end surface of said solid propellant. Accordingly, the blank cartridge according to this invention can be readily ignited by percussing that portion of the firing sheet uncovered by the end surface of solid propellant between an anvil and firing pin of a gun.

As described above, in order to obtain a structure in which a portion of priming composition layer is uncovered by the bottom surface of solid propellant, said uncovered portion of the priming composition layer must have self-supporting property. In this invention, this is achieved by employing a firing sheet prepared by impregnating or coating a padding material with a priming composition, thereby to produce a case less blank cartridge for small arms.

According to this invention, the cost of production of cartridges can be remarkably reduced by two factors, i.e., a metallic cartridge case is not employed and, other incombustible materials are not used at all, and at the same time the unloading operation of a waste cartridge case from a gun after firing is not necessary.

Accordingly, a feature of this invention is to provide a blank cartridge capable of being completely burnt out upon firing.

Another feature of this invention is to provide a means of ignition capable of effecting percussive ignition in a combustible blank cartridge.

Other numerous features and advantages of this invention Will readily be understood from the following description of several embodiments of this invention shown in the accompanying drawing, wherein FIG. 1 is a perspective view showing an embodiment of blank cartridge according to this invention.

FIG. 1a is a view in cross section of the blank cartridge of FIG. 1.

FIG. 1b is a plan view of the blank cartridge of FIG. 1.

FIG. 2 is a perspective view of another embodiment of blank cartridge according to this invention.

FIG. 2a is a view in cross section of the blank cartridge of FIG. 2.

FIG. 2b is a plan view of the blank cartridge of FIG. 2.

FIG. 3 is a sectional view of a third embodiment of blank cartridge according to this invention.

FIG. 4 is a sectional view showing the blank cartridge of FIG. 1 which has been sheathed.

FIG. 5 is a sectional view showing the blank cartridge of FIG. 2 which has been sheathed.

FIG. 6 is a sectional view showing the blank cartridge of FIG. 3 which has been sheathed.

FIG. 7 is a sectional view showing a state where the blank cartridge of FIG. 1 has been loaded within a combustion chamber of a gun.

FIG., 8 is a sectional view showing a state where the blank cartridge of FIG. 2 has been loaded within a combustion chamber of a gun.

FIG. 9 is a sectional view showing a state where the blank cartridge of FIG. 3 has been loaded within a combustion chamber of a gun.

In FIGS. 1, 1a and 1b, propellant 1 has previously been molded into a cylindrical shape, to one end of which a firing sheet 2 is provided as an igniting means. Firing sheet 2 is cut in the form of a circular base having a larger surface area than that of the bottom surface area of said propellant and adhered to the end surface of said propellant in such a manner that a portion of the surface is concentrically uncovered by the circumferential surface of the end of said propellant. As shown in FIG. 1a, the firing sheet used in this invention is composed of a material prepared by impregnating or coating padding material 5 with priming composition 4, which has selfsupporting property. Accordingly, the portion of the surface of firing sheet 2 uncovered by the circumferential surface of the end of the propellant will neither hang down nor bend over. In order to attach firing sheet 2 to propellant 1, an easily inflammable adhesive, for example, such as nitrocellulose and the like may be used. In FIGS. 1 and 1a, arrow A indicates the position at which percussion is effected by a firing pin of a gun.

In FIGS. 2, 2a and 2b, propellant 1a has previously been molded into a cylindrical shape in such a manner that it has a concave groove 3 in the wall surface of said propellant in the axial direction. Fixed to one end of said propellant is a firing sheet 2. Firing sheet 2 has been cut in the form of a circular base having the same diameter as the end surface of propellant 1a, and consequently when the firing sheet thus formed is adhered to the end surface of said propellant, only a portion of said firing sheet corresponding to the area of the aforesaid concave groove 3 remains uncovered by the end surface of said propellant. Accordingly, the abovementioned portion is percussed by a firing pin of a gun in a manner as shown by arrow A. As for firing sheet 2, the same material is used as in the blank cartridge of FIG. 1, namely, by impregnating or coating padding material 5 with priming composition 4.

In FIG. 3, propellant lb has previously been molded into a cylindrical shape having perforatoin 3a extended therethrough in the axial direction, to one end of which firing sheet 2 is fixed. Firing sheet has previously been cut in the form of a circular base having the same diameter as the end surface of said propellant, and consequently, when the firing sheet is adhered to the end surface of propellant 1b, only a portion of said firing sheet corresponding to the area of the perforation 3 remains uncovered by the end surface of said propellant. Accordingly, the above-mentioned portion is percussed by a firing pin of a gun in a manner as shown by arrow A. As for firing sheet 2, the same material is used as in the blank cartridges of FIGS. 1 and 2, namely, by impregnating or coating padding material 5 with priming composition 4.

After being suitably packaged, the blank cartridges respectively shown in FIGS. 1, 2 and 3 can be oflered in the market, as they are. However, as shown in FIGS. 4, 5 and 6, said cartridge may be enclosed in a sheath of easily combustible thin film 6 in order to provide better safety in handling thereof. As for the composition of easily combustible thin film 6, nitrocellulose is mostly preferred. However, such materials as those prepared by mixing nitrocellulose with a coloring agent such as dye, pigment, metal powder and the like, or also pigment, metal powder or the like in the presence of other film forming agents such as shellac, silicon oil and synthetic resin adhesives, can be used. As a metal powder, aluminum, zinc and the like is used.

When the blank cartridges having the above-mentioned structures in accordance with this invention are loaded in guns having the structures of combustion chambers for blank cartridge as shown in FIGS. 7, 8 and 9, these cartridges can be easily fired by the percussion fire method.

That is, when the blank cartridge having a structure as shown in FIG. 1 is loaded in combustion chamber 7 having shoulder 8 on the upper circumferential edge thereof in a manner as shown in FIG. 7, a portion of firing sheet 2 concentrically uncovered by the end surface of propellant 1 is percussed between said shoulder 8 and firing pin 9 to readily fire, while shoulder 8 acts as an anvil. 10 is a flash hole.

The blank cartridge having the structure as shown in FIG. 2 is loaded in combustion chamber 7 having shoulder 8 on the upper edge of raised rail 11 on the inside wall thereof. Raised rail 11 is firmly inserted into concave groove 3 of propellant 1a to introduce said propellant into said combustion chamber 7 so that an uncovered portion of firing sheet 2 is supported by shoulder 8. Accordingly, when an opposite portion corresponding to an uncovered portion of said firing sheet is percussed by firing pin 9, firing sheet 2 is readily fired while shoulder 8 acts as an anvil. 10 is a flash hole.

The blank cartridge having the structure as shown in FIG. 3 is loaded in combustion chamber 7 having projected portion 11a in the center thereof. Projected portion 11a is inserted into perforation 3a in a manner as shown in FIG. 9 so that firing sheet 2 may be supported by the upper surface of projected portion 11a. Accordingly, when an opposite portion of firing sheet cor responding to the surface thereof supported by upper surface of 8a of projected portion 11a is percussed by firing pin 9, firing sheet 2 is securely fired while upper surface 8a acts as an anvil. 10 is a flash hole.

As mentioned hereinbefore, by employing a firing sheet as an igniting means, this invention made it possible to effect a percussive ignition in a caseless blank cartridge, which has heretofore been considered difficult, and on the basis of the results, a completely combustible blank cartridge has been produced which is of practical use. As a result, the operation of unloading a waste cartridge from a gun is entirely unnecessary, whereby the efficiency of handling thereof has been raised. Further, a sharp reduction in the unit cost price of the cartridge is obtained because the ordinary expensive metallic cartridge case is not used.

As for the propellant used in this invention, there may be employed those prepared by bonding conventionally known small grain smokeless powder with adhesive and molding it into a desired shape, and solid propellant previously extruded and molded into desired shapes or solid propellant consisting of a porous single body.

As for the padding material of the firing sheet, fibrous stubstances such as paper, cloth and the like may be used. The preferred material is a thin, coarse and reticulated sheet. As for the priming composition used in the firing sheet, there may be used the initial explosive such as diazodinitrophenol (DDNP), lead trinitroresorcinate, and the like, in a single base, or a mixture prepared by suitably mixing these initial explosives with oxidizing agents such as potassium chlorate, barium nitrate, potassium nitrate and the like, and reducing agents such as antimony trisulfide, calcium silicate and the like.

Example 1 Solid propellant was prepared by mixing ball powder (32-80 mesh) with 1% of nitrocellulose dissolved in a mixed ethanol/ether solution to swell and dissolve the surfaces of grains of said ball powder and, compressing and molding the resultant mixture into a cylindrical shape while driving out the solvent. An average weight of powder charge per one gram solid propellant thus obtained was found to be 0.15 g. The firing sheet was obtained by mixing a priming composition of DDNPKCIO (mixing ratio 50:50) with 3% of crude rubber dissolved in a toluol solution to obtain a muddy mixture, coating a thin and coarse cotton fabric sheet with the resultant muddy mixture an after being dried, cutting the resultant cotton fabric sheet into a circular base having a diameter larger than that of the aforesaid solid propellant. The weight of the priming composition retained per gram of firing sheet thus obtained was 3035 mg. The thus obtained firing sheet was adhered to one end surface of the aforesaid solid propellant with Cemedain (a trade name), a nitrocellulose adhesive, to obtain a combustible blank cartridge of the type as shown in FIG. 1.

The thus obtained blank cartridge was subjected to a firing test with a fastening tool known as a Hilty gun (D x l00L) which is commercially available. As a result, it was observed that no combustion residues are produced at all therein. Further, its power was tested according to the piercing strength of a pin fired against an iron plate to show the result that the power is almost equal to that of a conventionally known bank cartridge with a case. In the above tests, an LH 440 pin (produced by Nippon Drive-it K.K.) was used as the pin, and a mold steel plate (SS 41 J. I. S.) of 9 mm. thickness as the iron plate.

Example 2 The blank cartridge obtained in Example 1 was sheathed with a material prepared by dispersing aluminum powder in a toluol solution containing 5% of chlorinated rubber to obtain a combustible blank cartridge of the type as shown in FIG. 4.

The thus obtained blank cartridge was subjected to firing and piercing tests using the same procedures as in Example 1. As a result, it was found that no combustion residues are produced and, that the power is almost equal to that of conventionally known blank cartridges with case.

Example 3 Solid propellant was obtained by mixing a single base composition of propellant for a hunting shot gun with a mixed ether/ethanol solution, extruding and molding the resultant mixture into a cylindrical and cord-like shape and then cutting the resultant product to a desired size. An average weight of powder charge per gram of solid propellant thus obtained was 0.15 g. The fin'ng sheet was prepared by mixing a priming composition of DDNP- Ba(NO (mixing ratio 70:30) With a toluol solution containing of thermoplastic elastomer Thermoplastic ST-125 (a trade name of product produced by Shell Chemical Co. in U.S.A.) to obtain a muddy mixture, coating a thin and coarse cloth with the resultant muddy mixture, drying the thus coated cloth and then cutting the dried cloth into a circular base having a diameter larger than that of the aforesaid solid propellant. The weight of the priming composition retained per gram of firing sheet thus obtained was 30-35 mg. The thus obtained firing sheet was adhered to one end surface of the aforesaid solid propellant with Cemedain to obtain a combustible blank cartridge of the type as shown in FIG. 1.

The thus obtained blank cartridge was subjected to firing and piercing tests according to the same procedures as in Example 1. As a result, it was found that no combustion residues are produced at all and, that the power is almost equal to that of conventionally known blank cartridges with case.

Example 4 The blank cartridge obtained in Example 3 was sheathed with a material prepared by admixing Rhodamine B (a product produced by Hodogaya Chemical K.K.) dissolved in methanol with an ethyl acetate solution containing 2% of nitrocellulose to obtain a combustible blank cartridge of the type as shown in FIG. 4.

As a result of subjecting the thus obtained blank cartridge to firing and piercing tests according to the same procedures as in Example 1, it was also found that no combustion residues are produced and, that the power is almost equal to that of conventionally known blank cartridges with case.

Example 5 Solid propellant was obtained by mixing a single base composition of propellant for a hunting shot gun, to which 70% of KNO of 40-80 mesh based on the weight of the single base composition has been added, with a mixed ether/ethanol solution, extruding and molding the resultant mixture into a cylindrical and cord-like shape and then cutting the resultant product in a desired shape and size while eluding out KNO therefrom by rinsing with water in a state where the solvent is still contained therein. The thus obtained solid propellant was a porous single body solid propellant having perforations at the portions from where KNO has been eluded out, and having an average weight of powder charge of 0.15 g. per gram of solid propellant. The firing sheet was obtained by mixing a priming composition consisting of a mixture of DDNP-Ba(NO -aluminum powder (mixing ratio 70:28:2) with a toluol solution containing 10% of thermoplastic elastomer Kaliflex-KIOI (a trade name of a product produced by Shell Chemical Co. U.S.A.) to obtain a muddy mixture, coating a thin and coarse paper tape with the resultant muddy mixture, drying the thus coated paper tape and then cutting the dried paper tape into the shape of a circular base having a diameter larger than that of the aforesaid solid propellant. The weight of the priming composition retained per gram of firing sheet thus obtained was 25-30 mg. The thus obtained firing sheet was adhered to one end surface of the aforesaid solid propellant with Cemedain to obtain a combustible blank cartridge of the type as shown in FIG. 1.

As a result of subjecting the thus obtained blank cartridge to firing and piercing tests according to the same procedures as in Example 1, it was found that no combustion residues are produced and, that the power is almost equal to that of conventionally known blank cartridges with case.

Example 6 The blank cartridge obtained in Example 5 was sheathed with a material prepared by dispersing graphite in an alcohol solution containing 5% vinylacetate polymer to obtain a combustible blank cartridge of the type as shown in FIG. 4.

As a result of subjecting the thus obtained blank cartridge to firing and piercing tests according to the same procedures as in Example 1, it was found that no coinbustion residues are produced and, that the power is equal to that of conventionally known blank cartridges with case.

Example 7 Solid propellant was obtained by extruding with cornpression and molding the same composition as in Example 3 into a cylindrical and cord-like shape having one concave groove on the outside wall thereof in the axial direction, and cutting the resultant product to the desired size. An average weight of powder charge per gram of solid propellant thus obtained was 0.15 g. The firing sheet was obtained by cutting the same material as in Example 3 into a circular base having the same diameter as that of the aforesaid solid propellant. The weight of the priming composition retained per gram of firing sheet thus obtained was 25-30 mg. The thus obtained firing sheet was adhered to one end surface of the aforesaid solid propellant with Cemedain to obtain a combustible blank cartridge of the type as shown in FIG. 2.

As a result of subjecting the thus obtained blank cartridge to firing and piercing tests according to the same procedures as in Example 1, it was found that no combustion residues are produced and, that the power is equal to that of conventionally known blank cartridges with case.

Example 8 The blank cartridge obtained in Example 7 was sheathed with a material prepared by dispersing aluminum fine powder in a toluol solution containing 45% of chlorinated rubber to obtain a combustible blank cartridge of the type as shown in FIG. 5.

As a result of subjecting the thus obtained blank cartridge to firing and piercing tests according to the same procedures as in Example 1, it was found that no combustion residues are produced and, that the power is substantially equal to that of conventionally known blank cartridges with case.

Example 9 Solid propellant was obtained by extruding with compression and molding the same composition as in Example 3 into a cylindrical and cord-like shape having a perforated hole extended therethrough and cutting the resultant product to a desired length. An average weight of powder charge per gram of solid propellant thus obtained was 0.15 g. The firing sheet was obtained by cutting the same material as in Example 3 into a circular base having the same diameter as the aforesaid solid propellant. The weight of the priming composition retained per gram of firing sheet thus obtained was 25-30 mg. The thus obtained firing sheet was adhered to one end surface of the aforesaid solid propellant with Ce'medain to obtain a combustible blank cartridge of the type as shown in FIG. 3.

As a result of subjecting the thus obtained blank cartridge to firing and piercing tests according to the same procedures as in Example 1, it was found that no combustion residues are produced and, that the power is substantially equal to that of conventionally known blank cartridges with case.

Example I The blank cartridge obtained in Example 9 was sheathed with a material prepared by dispersing aluminum fine powder in a toluol solution containing of chlorinated rubber to obtain a combustible blank cartridge of the type as shown in FIG. 6.

As a result of subjecting the thus obtained blank cartridge to firing and piercing tests according to the same procedures as in Example 1, it was found that no combustion residues are produced and, that the power is substantially equal to that of conventionally known blank cartridges with case.

We claim:

1. A combustible blank cartridge which comprises a monolithic body constituted of porous solid propellant, said body having opposite ends, and a firing sheet placed on one end of the propellant body, said body covering a portion of one surface of said sheet and leaving a portion of said one surface exposed, so that said exposed portion in cooperation with gun structure can be percussed by a firing pin.

2. A cartridge according to claim 1 wherein the firing sheet has a larger surface cross-sectional area than the adjacent surface of the propellant body and therefore extends therebeyond.

3. A cartridge according to claim 2 wherein said firing sheet is of sufficiently rigid construction to be selfsupporting in shape.

4. A cartridge according to claim 3 wherein said propellant body is cylindrical and said firing sheet is discshape and concentric with said body.

5. A cartridge according to claim 3 wherein said firing sheet is a fibrous material containing a priming composition.

6. A cartridge according to claim 3 comprising a sheath enclosing said propellant body and firing sheet, said sheath being constituted of inflammable thin film mate rial.

7. A cartridge according to claim 1 wherein the propellant body is elongated and has at least one concave groove in the peripheral surface thereof extending axially, the firing sheet and body having adjoining surfaces of the same shape and size so that the uncovered, exposed portion of the sheet is at said concave groove.

8. A cartridge according to claim 7 wherein said propellant body is cylindrical and said firing sheet is discshape and concentric with said body.

9. A cartridge according to claim 7 wherein said firing sheet is a fibrous material containing a priming composition.

10. A cartridge according to claim 7 comprising a sheath enclosing said propellant body and firing sheet, said sheath being constituted of inflammable thin film material.

11. A cartridge according to claim 1 wherein the propellant body is elongated and is provided with a hole extending axially therethrough and the firing sheet and body have adjoining surfaces of the same shape and size so that the uncovered, exposed portion of the sheet is at said hole.

12. A cartridge according to claim 11 wherein said propellant body is cylindrical and said firing sheet is discshape and concentric with said body.

13. A cartridge according to claim 11 wherein said firing sheet is a fibrous material containing a priming composition.

14. A cartridge according to claim 11 comprising a sheath enclosing said propellant body and firing sheet, said sheath being constituted of inflammable thin film material.

References Cited UNITED STATES PATENTS 49,474 8/1865 Holden 102-865 2,407,264 9/ 1946 Ferrel 102-865 2,568,079 9/1951 McGahey 102-45 X 2,703,529 3/1955 Tuckerman et a] 102-43 2,982,211 5/1961 Beal et a1. 102-43 3,008,258 11/1961 Johnson 102-38 X 3,311,057 3/1967 Quinlan et a1. 102-38 ROBERT F. STAHL, Primary Examiner.

US. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 156 Dated March 18, 1969 Inventor(s) Teruhlko Suzukl: et 31 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4-, line 53: change "one gram" to --one. Column line 62: change "gram of" to --one--. Column l, line 75: change "bank" to -blank-. Column 5, line 23: change "gram of to one--. Column 5, line 27: change "toluol to -toluene--.

Column 5, line 35: change "gram of" to -one--. Column 5, line 7 change "gram of" to --one-. Column 5, line 10: change "gram of" to --one--. Column 6, line 40: change "gram of" to --one--.

Column 6, line -!-5: change 'gram of" to --one. Column 6, line 60: change "toluol" to --toluene--. Column 7, line 1: change "gram 0E" to --one--. Column 7, line 6: change "gram of" to --one--. Column 7, line 20: change "toluol" to toluene-.

s rifitl Mu SEALED JAN 191971 mmumlr. Ill-l. .m. Awning 0m d-iulm ot Patents 

